TurboChef Technologies TurboChef - Manual (Page 59)

THE CONVECTION CIRCUIT 47
The Convection Circuit provides the high-temperature
airflow required to brown and cook food items.
CONVECTION CIRCUIT COMPONENTS
The following is a description of each component
within the Convection Circuit and how each acts
within the circuit. Figure 37 below shows a block dia-
gram of the Convection Circuit.
Main Convection Heater
The main convection heater is an open-coil style
heater rated at 3300 watts at 208 VAC with a resist-
ance of 13.11 Ohms. The convection heater
is controlled by the K4 solid state relay.
Convection Motor
The convection motor is a brushless AC switch reluc-
tance type. Its top speed is 7100 RPM at 1 HP. The
motor is controlled by a proprietary controller.
Motor Controller (BMSC)
The motor controller is proprietary and will only
operate the convection motor described above. The
motor controller is controlled on command from the
I/O control board and a 0-10VDC speed command
from the I/O control board.
High Limit Thermostat
The high limit thermostat is a 250 VAC, 3-pole,
manual reset thermostat with a trip point of 572ºF
(300ºC). The thermostat, which interrupts power to
both the main convection heater and the IR element,
should never operate during normal oven operation.
BMSC
BLWR
MTR
M4 GREEN
M3 WHITE
M2 RED
M1 BLACK
4
3
2
1
240 VAC
3 PHASE
OUT
200-240
VAC IN
3
2
1
SPD CMD
1
2
3
4
5
6
0-10V
I/O COM
ENABLE
I/O COM
STATUS OK
I/O COM
L2
L1
OR-9
BL530 BL500
OR540
BL510
K5 K4
B1
B2
A1
A2
SSR
HT520
WH-28
WH-30
RD-19
BR600
1
2
HX ELEMENT
3300 WATTS
13.1 OHMS
BOTTOM IR
3000 WATTS
14.4 OHMS
BOTTOM IR CONTROL
MAIN HX CONTROL
+24
C NC
32 31
C NC
22 21
C NC
12 11
OT1 - HI-LIMIT
MANUAL RESET
MOTOR SPINS
COUNTER-CLOCKWISE
FROM BACK
RD-24
BK-25
WH-31
BK-32
GROUND (GREEN)
L2
L1
F I G U R E 37: Convection Circuit Block Diagram